You can determine your kernel version with the following case-sensitive shell command:

uname -r

The default stack size in original Red Hat Enterprise Linux 5.x kernels is only 4K and the drivers are known to require more than that in some cases. You can either rebuild your own custom kernel, or install one of the "stk16" kernels below which we have provided for your convenience. They are essentially identical to the Red Hat kernels, except that the stack size was increased to 16K.